Color Octet Contribution in Exclusive P-Wave Charmonium Decay

Recent advances in our understanding of the higher-wave quarkonia have generated much interests in quarkonium physics. However most are devoted to inclusive decays and productions. Experimental data of several two-body exclusive decay channels of P-wave charmonia such as \pi \pi and p \bar p are available and some have recently been re-measured by the BES collaboration. It is not clear from the outset that color octet is needed for these exclusive channels. Indeed only color singlet has been used in the past and reasonable agreement with data was found. Contrary to these old results, we provide theoretical arguments for the inclusion of color octet and perform explicit calculations to back this up.Comment: 6 pages using espcrc2.sty, contribution to the 4th Int. Conference on Hyperons, Charm and Beauty Hadrons, Valencia, June 200

Monolayer protection for eletrochemical migration control in silver nanocomposite

©2006 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/?APPLAB/89/112112/1DOI:10.1063/1.2353813The authors introduced an effective approach of using monolayer-protected silver nanoparticles to reduce silver migration for electronic device interconnect applications. Formation of surface complex between the carboxylate anion and surface silver ion reduces the solubility and diffusivity significantly of migration components and therefore contributes to effective migration control. A fundamental understanding of the mechanism of silver migration control was conducted by studying the current-voltage relationships of the nanocomposites with a migration model. The control of silver migration enables the application of the silver composites in fine pitch and high performance electronic device interconnects

Panoramic-reconstruction temporal imaging for seamless measurements of slowly-evolved femtosecond pulse dynamics

Single-shot real-time characterization of optical waveforms with sub-picosecond resolution is essential for investigating various ultrafast optical dynamics. However, the finite temporal recording length of current techniques hinders comprehensive understanding of many intriguing ultrafast optical phenomena that evolve over a time scale much longer than their fine temporal details. Inspired by the space-time duality and by stitching of multiple microscopic images to achieve a larger field of view in the spatial domain, here a panoramic-reconstruction temporal imaging (PARTI) system is devised to scale up the temporal recording length without sacrificing the resolution. As a proof-of-concept demonstration, the PARTI system is applied to study the dynamic waveforms of slowly-evolved dissipative Kerr solitons in an ultrahigh-Q microresonator. Two 1.5-ns-long comprehensive evolution portraits are reconstructed with 740-fs resolution and dissipative Kerr soliton transition dynamics, in which a multiplet soliton state evolves into stable singlet soliton state, are depicted

University lecturers’ construction of the ‘ideal’ undergraduate student

Research on the ‘ideal’ or ‘good’ student tends to be situated within compulsory schooling. Few recent studies have focused on lecturers’ conceptualisation and construction of the ‘ideal’ university student. Informed by 30 in-depth interviews with lecturers from two post-92 English universities within the social sciences, we explore how the notion of ‘ideal’ student is understood in contemporary higher education. We focus on lecturers’ expectations of undergraduate students, as well as their views of the ‘ideal’ student in different teaching and learning contexts. We identified specific personal and academic skillsets that are desirable of students, including preparation, engagement, commitment, as well as being critical, reflective and progressing. The ability to achieve high grades, interestingly, is rarely mentioned as important. Implications for policy and practice are discussed as we present a much-needed update on the current features of the ‘ideal’ university student, which can influence student experience, especially the lecturer-student relationship